Field of the Invention
The present invention relates to inkjet printing apparatuses.
Description of the Related Art
Japanese Patent Laid-Open No. 2006-240174 discloses a technique of counting the number of ink discharges from discharge ports of a print head and performing a recovery process by removing ink adhered on a discharge port surface of the print head by using a wiping member in accordance with the counted discharge value. According to this technique, the discharge port surface of the print head can be effectively cleaned off.
However, it has become evident that the discharge port surface of the print head sometimes cannot be sufficiently cleaned off with the technique disclosed in Japanese Patent Laid-Open No. 2006-240174. Specifically, in an inkjet apparatus of a serial type in particular, an air current (self-generated air current) occurring with the discharging of ink droplets and an air current (inflow air current) occurring with the movement of the print head cause an upward vortex (vortex current) to occur. When floating mist (also called ink droplets in the atmosphere or simply mist) within the printing apparatus becomes caught in the vortex current, the floating mist travels with the vortex current and adheres to the discharge port surface of the print head.
Moreover, according to further studies, it has been found that, when the print head moves, the inflow air current becomes larger toward the discharge port array located at the front side in the moving direction of the print head, whereas the inflow air current becomes smaller toward the discharge port array located at the rear side. Thus, when the print head moves, the ink discharged from the front discharge port array in the moving direction tends to rise more as floating mist, thus causing the amount of floating mist adhering to the vicinity of that discharge port array to increase.